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authorBob Peterson <rpeterso@redhat.com>2013-09-11 13:44:01 -0500
committerSteven Whitehouse <swhiteho@redhat.com>2013-09-17 10:14:39 +0100
commit6aa7640f306a1dd0923d29d9190c5686907d5140 (patch)
treede2d5f54bbbeccd2aaa996eeceba8bd696b7d978
parent0d0d110720d7960b77c03c9f2597faaff4b484ae (diff)
GFS2: optimize rbm_from_block wrt bi_start
In function gfs2_rbm_from_block, it starts by checking if the block falls within the first bitmap. It does so by checking if the rbm's offset is less than (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY. However, the first bitmap will always have bi_start==0. Therefore this is an unnecessary calculation in a function that gets called billions of times. This patch removes the reference to bi_start. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
-rw-r--r--fs/gfs2/rgrp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 69317435faa7..7a6fa03bb32a 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -262,7 +262,7 @@ static int gfs2_rbm_from_block(struct gfs2_rbm *rbm, u64 block)
rbm->bi = rbm->rgd->rd_bits;
rbm->offset = (u32)(rblock);
/* Check if the block is within the first block */
- if (rbm->offset < (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY)
+ if (rbm->offset < rbm->bi->bi_len * GFS2_NBBY)
return 0;
/* Adjust for the size diff between gfs2_meta_header and gfs2_rgrp */